Provision of an individual video display for each of the passenger seats in a passenger vehicle such as an aircraft has been disclosed in U.S. Pat. No. 4,584,603, issued Apr. 22, 1986 to Harrison. In the system of U.S. Pat. No. 4,584,603, the passenger seats are provided with video displays A control apparatus supplies a plurality of video signals in parallel to each display. The video display at each passenger seat selects one of the video signals and displays the selected video signal.
In the system of U.S. Pat. No. 4,584,603, each signal supplied to the video displays is transmitted through respective independent transmitting lines (one for each video display) to the respective video displays. In order to transmit many signals to each display, many transmission lines are required for each display. As a result, the system wiring is very complicated, and the arrangement of the overall system is also very complicated. If the U.S. Pat. No. 4,584,603 system would be modified to be capable of two way communication, so that each of the video displays could transmit information (such as information regarding the condition of the associated seat) to the control apparatus, even more transmission lines would be required, so that the system would become even more complicated. It would be almost impossible to wire these transmission lines in a large aircraft such as one having more than 500 seats. It would be desireable to eliminate this problem, by providing a two way communication system capable of transmitting many information signals in two directions and without complicated wiring in a passenger vehicle such as an aircraft.